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1、ModernfrequencychangertechnicalanalysisChengXi(Heilongjianglongrnaymininggroupco.,ltd.)Thegeneralfrequencychangerbyitsmeritsandsoonintellectualization,digitization,networkreceivespeople'sfavormoreandmare,butalongwiththegeneralfrequencychangerapplicationscope'sexpansion,exposess
2、amequestions.Inviewofthesequestions,thisarticlecarriedonhasanalyzedandproposedthecountermeasure.First,overtanequestionandcaunterljeasure.Thegeneralfrequencychangefsmaincircuitformgenerallybytherectificationpart,thecontravariantpartandthefilterpartiscomposed.Therectificationpart
3、forthethree-phasebridgE-typeuncontrolledrectifier,theinventorspartistheIGBTthree-phasebridge-typeinventors,andtheoutputisthePWMprofile.Becausethegeneralfrequencychangefsrectificationpartusesthediodeuncontrolledbridge-typelevelingcircuit,themiddlefilterpartusesthebigelectriccapa
4、citytotakethefilter,thereforerectifiersinputcurrentinfactiscapacitor'schargingcurrent,assumesahighermoreandprecipitouspulsewave,itsharmoniccomponentisbig.Fortheharmoniccancellation,tllayuse:1、Increasesthefrequencychangerelectricpowersupplyinternalresistance.Usuallyinthesituatio
5、n,powerequipment'sinternalresistancemayplaythecushionfrequencychangerconcurrentfilterelectriccapacityrsreactivepowerrole.Thisljindofinternalresistanceistransformersshort-circuitimpedance.Whenpowersourcecapacityrelativefrequencychangercapacityhour,thentheinternalresistancevaluer
6、elativelyisbigger,theharmoniccontentissmaller;Whenthepowersourcecapacityrelativefrequencychangercapacityisbigger,thentheinternalresistancevaluerelativelyisbigger,theharmoniccontentisbigger.Thereforebestchoiceshort-circuitimpedancebigtransformer.2、Installsthereactor.Installsther
7、eactorisactuallyincreasesthefrequencychangerelectricpowersuppl犷sinternalresistancefrarnexterio匸Installsthedirect-currentreactorinfrequencychangefsexchangesideinstallmentexchangereactororinfrequencychangefsdirect-cuiTentside,alsoorinstalls,suppressestheharmoniccurrent.3^Transfor
8、merheterogeneitymovement.Thegeneralfrequencychangefsre
